The automatic dependent surveillance broadcast (ADS-B) system a flight information system which integrates communication and surveillance. The ADS-B system specifies parts of signal source, information transmission channel and information processing and display. Without manual labor, The ADS-B system of an aerial vehicle automatically broadcasts information related to the aerial vehicle to other aerial vehicles and terrestrial receiving devices within a certain range, wherein the information related to the aerial vehicle comprises precise location and height, for example. The application of ADS-B technique in the civil aircraft field has been actively promoted.
The application of the radar ranging technique in the active mobile safety has developed from 24 GHz to 48 GHz and 77 GHz, and the scanning range of the radar ranging technique can reach 150 meters. The radar ranging technique is advantageous of probing the far object in both of day and night without being affected by the cloud, frog and rain. That is, the radar ranging technique is has the characteristics of all day and all weather and certain penetration, such that the radar ranging device is the essential electronic device in the commercial practice or scientific research.
The application of unmanned aerial vehicle (UAV) has been developed maturely, and the UAV can be controlled by the operator on the land for geography exploring, aerial photography or other commercial application. However, the high-altitude space is not unregulated and obstacle-free. As time goes, the number and usage of UAVs increase, and the probability that the UAV mistakenly enters the flight prohibited area also increases. As well as the obstacle in the flight space of the UAV, the aerial safety between the UAVs or the UAV and the aerial vehicle should be carefully considered when the UAV is flying.